Abstract

During the last decade, the demand for peppers and pepper-based products has increased significantly. This higher demand is explained in part because of enhanced functional properties and the associated health benefits (beta carotene, vitamin A and vitamin C, and Capsaicin). The remarkable variety of fruit color in Capsicum species is explained in part because the chlorophyll degradation and beta-carotenes synthesis during fruit ripening process among others, which is under genetic and environmental regulation. The color expression in Capsicum fruits and those genes associated to its control is still unlocked. During this study we studied the fruit chlorophyll degradation and some carotenoid pigments accumulation such as capsorubin, capsanthin and zeaxanthin by HPLC in red-fruits (A-571, A-1777, A-664), yellow fruits (A-580, A-583) and dark-brown fruits (A-612, A-658). Also, Lycopene-b-cyclase (-LCY) gene and Capsanthin-capsorubin synthase (CCS) gene were amplified, and then sequenced for further gene expression studies. The gene expression was followed by RT-PCR and qRT-PCR. Differences were observed in chlorophyll content and betacarotenes according to the fruit color; while in dark-drown fruit less chlorophyll degradation was detected in conjunction with higher CCS gene expression, in Yellow fruits chlorophyll degradation was almost complete and CCS expression null. Yellow fruits showed Zeaxanthin accumulation but not Capsorubin or Capsanthin accumulation. The studied gene sequences in the seven Capsicum accessions were highly conserved in relation to the previous reported sequences, supporting that CCS expression fails in the Yellow accessions (A-580 and A-583).